Punching apparatus for work on continuously moving webs in bag-making machines



United States Patent Inventors Kurt Rochla;

Karl-Heinz Trautmann, Lengerich of Westphalia, Germany Appl. No. 697,829 Filed Jan. 15, 1968 Patented Dec. 8, 1970 Assignee Winrlmoller & Holscher Lengerich of Westphalia, Germany Priority Feb. 13, 1967 Germany No. W43348 PUNCHING APPARATUS FOR WORK ON CONTINUOUSLY MOVING WEBS IN BAG- MAKING MACHINES 4 Claims, 3 Drawing Figs.

US. Cl 83/185, 83/328 Int. Cl. B26d 1/56 Field of Search 83/324,

[56] References Cited UNITED STATES PATENTS 665,702 l/ 1901 Stimpson 83/700X 2,262,919 l1/l94l Bruker 83/328X 2,407,253 9/1946 Conner 83/327X 2,947,184 8/1960 Olson 83/324X 3,069,303 12/1962 Scholle 93/8X 3,144,814 8/1964 Lokey 93/8 3,333,495 8/ 1967 Stuchbery et al. 83/328X 846,362 3/1907 Swift, Jr 83/328X FOREIGN PATENTS 602,154 2/1960 ltaly 83 349 Primary Examiner-James M. Meister Attorney-Fleit, Gipple & Jacobson ABSTRACT: A flat carrier is movable parallel to itself and to the web on revolving carrying elements and carries the punching tools for producing all punched cuts which are to be formed in a workpiece section and spaced in the direction of travel of the web.

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Kurt ROCHLA Karl-Heinz TRAUTMA N N By 7 111 366 WWW/4L their A TORNEYS lUNCIIING APPARATUS FOR WORK ON CONTINUOUSLY MOVING WEBS IN BAG-MAKING MACHINES This invention relates to a punching apparatus for treating continuously moving webs, particularly of plastics material sheeting, in bagmaking machines. In the manufacture of numerous known types of bags, various punching operations succeeding in the longitudinal direction of the bag must be perparatus, space and setting-up time when a change to workpiece sections of different lengths was desired. Besides, difficulties could be involved in the maintenance of the registry of the punched cuts produced by a succeeding punching device with those produced by a preceding punching device.

It is anobject of the invention to providea punching apparatus in which the disadvantages of the known apparatus which have been described above are avoided and in which there is no need to provide a pluralityof individual punching devices which are individually driven and require individual adjustment and serve for producing punched cuts spaced in the longitudinal direction of the web.

According to the invention this object is accomplished in that a flat carrier is provided, which is moved parallel to itself and to the web on revolvingcarrying elements and carries the punching tools for producing all punched cuts which are to be formed in a workpiece section and spaced in the direction of travel of the web. Because all punching tools are moved to the web at the same time by the common carrier, the previously existing need for individual punching devices and expensive separate drive units is eliminated. As a result, the bagmaking machine is simplified and its space requirement is reducedso I that the product can be made at lower cost.

If the tools consist of heated punching tools for producing punched cuts in .webs of thermoplastic sheeting, the fact that the tool carrier is moved parallel to itself and to the web by revolving carrying elements, in accordance with the invention,

results in the further advantage that the cutting tools can be supplied with electric heating current in a very simple manner. Whereas the previously usual, revolving tools required an expensive current supply and return system comprising slip rings, tli'e supply of current to the tool carrier which is moved parallel to itself, and the return of current from such carrier, may be effected by means of simple flexible electric cables because these cables cannot be twisted about their axis.

In a development of the invention, the tools may be adjustably arifl replaceably mounted on the tool carrier so that the apparatus can be used in the manufacture of any desired bags, including bags which do not require punched cuts spaced in the direction of travel of the bag. The tool carrier consists preferably of two parallel frame rods, which are mounted each for eccentric rotation in two revolving carrying elements, and of rods which carry the tools and are adjustably secured to and connect the frame rods. The frame rods may be pivoted to the revolving carrying elements by means of brackets, which extend at right angles to the longitudinal direction of the frame rods, each frame rod having one bracket rigidly secured to it and one bracket which is rotatably mounted on the frame rod. The rotatable mounting of one bracket enables a compensation of slight inaccuracies in the mountings and of a small play of the revolving carrying elements.

For work on tubular webs, the backing tools which cooperate with the punching tools of the tool carrier may be mounted on a carrier which is held stationary in the tubing in known manner. This will be required, e.g. when seamless tubing of plastics materialis to be formed with punched cuts for the formation of thumb notches in only one ply of the tubing.

In a further embodiment of the invention, the revolving carrying elements may be adapted to be driven at a periodically changing angular velocity, in a manner known per se, so that a replacement of the carrying elements for the tool carrier is not required for an adjustment of the apparatus to workpiece sections having different lengths whereas the speed of travel of the web remains constant.

The invention will be explained more fully hereinafter with reference to the drawing, which shows an embodimentby way of example.

FIG. 1 is a diagrammatic side elevation showing a punching apparatus according to the invention;

FIG. 2 is a top plan view showing the punching apparatus of FIG. 1; and

FIG. 3 is a sectional view taken on line IIlIlI in FIG. 2.

A shaft 2 is rotatably mounted in side frames 1 and 1' of the machine and is driven by a motor which is not shown. A gear 3 is secured to the shaft 2 for joint rotation and is in mesh with a gear 4, which is rotatably. mounted on a cantilever axle, which is nonrotatably mounted in the frame 1. A gear 5 is also rotatably mounted on the same axle and is driven from the gear 4 by a double sliding crank linkage. The latter transmits the uniform angular velocity of the gear 4 to the gear 5 as a nonuniform, periodically changing velocity. An accelerated angular velocity is produced during one-half of a revolution of the gear 5 and a retarded angular velocity during the succeeding half-revolution. The peak angular velocity is adjustable in known manner by means of the handwheel 6 and the toggle clamps 7, and 7'. The output gear 5 is in mesh with the idler gears 8 and 9, which are secured, to shafts 49 and 50 for rotation therewith to drive the gears 8 and 9, which are also secured to these shafts for rotation therewith. The gears 8, 8' and 9, 9' are in toothed mesh with the gears l0, l0 and 11, 11. The counterweights I2, 12' and 13, 13' are firmly connected to these gears. The counterweights are'circular and have leverlike extensions '40, 40' and 41, 41' extending inthe direction of the imaginary straight line which connects the center of gravity of each counterweight to-the center of the associated circle. The levers 40,40 and 41,41 have bores at g the intersections of the pitch circles of the gears 10, 10' and 11, 11' with said imaginary straight lines.

Frame rods 16 and 16 are rotatably mounted bybrackets 14, 14' and 15, 15' in the bores of the levers 40, 40' and 41, 41'. The brackets 14 and 14 are firmly screw-connected to the frame rods 16, 16 whereas the brackets l5, 15" are pivoted to the frame rods l6, l6. Pivoted brackets are used for the manufacturing reasons to enable a compensation of any slight play between the gears and particularly any inaccuracies in the spacing of the points where the brackets are connected to the frame rods and to the levers.

Each frame rod consists of two identical, rectangular spars l8 and 19 or 18 and 19'. These spars are firmly interconnected in their lower part by means which are not shown.

Rectangular-section bars 17, 20 or 17', 20' are screw-connected to these spars at the upper edges thereof so that a central slot having the desired width remains between the spars. This slot serves for the mounting of rods 23, which carry the tools 33, 33 and 35. a

The fixation is shown in FIG. 3. A stud 21 carries a disc 22, which bears from below on the bars I7, 20 when a tool-carry ing rod 23 provided with a bore is tightened by a nut 24 on the stud 21. The tools 33, 33' are carried by tool holders 42, which are slidable in the longitudinal direction of the rods 23 and can be clamped in the selected position. The tool 35 is firmly secured bya tool holder 43 to the associated rod 23.

Backing tools 34 and 34' for cooperation with the punching tools 33 and 33' are connected by clamps 38 to rods 27 which are secured to the two side frames 1 and l of the machine. For this purpose, the side frames of the machine are provided at the top with profiled rails 25, 25', on which sliders 26, 26' are slidable. The respective rod 27 is screw-connected to the sliders 26, 26' and extends between them. The sliders 26, 26' can be fixed in any desired position by toggle clamps 44 just as has been described for the rods 23 with reference to FIG. 3.

Any desired number of tool-carrying rods 23 can be provided throughout the length of the frame rods 16, 16'. According to the invention, the length of the frame rods l6, 16' is larger than the largest intended length of the workpiece section of the webs to be worked upon. As a result, the required punching operations can be performed simultaneously in two zones, which are spaced apart by the length of the workpiece section. This has the advantage that one and the same punching apparatus according to the invention can be used to carry out even punching operations which in view of their relative location cannot be performed jointly, e.g. where a two-ply web is to be worked upon and part of the punching cuts should be made in both plies whereas other punching cuts should be made only in one ply so that the plies must be separated for the latter cuts and the first-mentioned cuts cannot be performed in this area.

The web 29 to be worked upon is conveyed from the supply roll 28 in such a manner that the web is moved horizontally andon the level of the top edge of the side frames of the machine between three revolving endless belts 30, 31, and 32. The belts carry the web throughout the punching apparatus and to the succeeding working station.

When the tools 33, 33' and 35 are in their uppermost position, they cut into the web two rows of air holes 45 and 46. These rows are parallel to the subsequently formed transverse lines of severance. These tools cut also a thumb hole 47 into the web at a point where a bag end is subsequently formed. The rows 45 and 46 are punched by the punching tools 33 and 33' in cooperation with the backing tools 34 and 34'. The punching tools 33 and 33 may be replaced by needles, which pierce through the tubing 29. In this case, the backing tools must have corresponding apertures for receiving such needles. The thumb hole 47 is cut only into one ply of the tubing by the electrically heated tool 35 and with the aid of a framelike inner tool 36, which is disposed inside the tubing. The rollers 37 which are disposed outside the tubing and serve to retain the carrier for the inner tool are freely rotatably mounted in the frame by an accessory, which is not shown. These rollers serve only to locate the carrier for the inner tool 36.

The tools 33 and 33' for punching the series of air holes 45 and 46 are disposed at the entrance end, and the tool 35 for punching the thumb hole 47 is disposed at the exit end of the apparatus and spaced one workpiece section from tools 33 and 33'. The thumb hole can thus be punched only in one ply of the tubing in an area thereof in which rows of air holes are formed in both plies when they are in contact with each other whereas the tubing plies are separated during the punching of the thumb hole.

The spacing of the rows of air holes 45, 46 from the end of the bag is one-half of the distance between the punching tools 33 and 33. In a severing station 48, the tubing 29 is cut through midway between two rows of air holes 45 and 46. The thumb hole which has been only partly cut by the tool 35 is so disposed between the rows of air holes that it is completed by the severing cut. The tube section is subsequently closed at the opposite end.

The speed of the web 29 to be worked upon is not adjusted in accordance with the working speed of the punching and cutting apparatus but the horizontal speed of the tool carrier in its uppermost position is adjusted to the web speed. For this purpose, the double sliding crank linkage is provided between the gears 4 and 5. This linkage enables in known manner a periodically changing acceleration and retardation of the revolving parts and of the tools so that the apparatus can be adjusted for the manufacture of different bag sizes.

We claim:

1. An apparatus for processing continuously moving tubular webs in bagmaking machines, comprising a flat, elongated tool-carrier adapted to revolve parallel to itself and to the web, said carrier carrying a plurality of tools, spaced apart in its longitudinal direction, and a corresponding number of stationary backing tools arranged to cooperate with said tools, a

plurality of said backing tools being arranged beyond the tu ular web and at least one of said backing tools being arranged within the tubular web, the distance between said tools being such that with each working cycle of said carrier a plurality of web units is simultaneously processed.

2. An apparatus according to claim 1, wherein the tools are adjustably and removably mounted on the tool carrier.

3. An apparatus according to claim 1, wherein the tool carrier consists of two parallel frame rods, which rods are mounted each for eccentric rotation on two revolving carrying elements and further consists of rods which carry the tools and which are adjustably secured to and connect the frame rods.

4. An apparatus according .to claim 3, wherein the frame rods are pivoted to the revolving carrying elements by means of brackets which extend at right angles to the longitudinal direction of the frame rods, each frame rod having one bracket rigidly secured to it and one bracket rotatably mounted on it. 

